Rebellion Racing plans to use this weekend's Spa round of the World Endurance Championship in Belgium as an extended test session for its new R-One LMP1 contender.

The Anglo-Swiss team will give its pair of ORECA-designed and -built R-Ones a delayed race debut in Saturday's Spa 6 Hours after falling back on its old Lola coupes at the Silverstone series opener last month. The delays mean that the two Toyota-powered R-Ones have covered only around 1000 km (620 miles) between them at Paul Ricard going into the race.

Rebellion team manager Bart Hayden said, "We aren't treating this weekend as a race, because we have a job list as long as your arm — this is about the next step on the road to the Le Mans 24 Hours.

"We don't have massive expectations; we just want to get as many laps as we can on the cars, even if that means going in and out of the box to affect repairs.

"We could have stayed at Ricard and done more test miles, but a race weekend really focuses the mind. We wanted a race under our belt before we go to Le Mans."

The first R-One undertook a shakedown in the week of the Silverstone race and subsequently completed 800 km (500 miles) over the course of a two-day test at Ricard at the end of last week. The second chassis completed approximately 160 km when both cars were shakedown prior to leaving for Spa at Ricard on Monday.

Nicolas Prost, who shares the No. 12 car with Nick Heidfeld and Mathias Beche, said he was impressed by the R-One during the test.

"It feels much closer to a single-seater than the Lola. You can tell the weight is low down and it is so much more reactive, so I am feeling very positive," he said.

Prost, Heidfeld and Beche have done the bulk of the testing so far.

Andrea Belicchi gave the second car its shakedown, with teammates Fabio Leimer and Dominik Kraihamer yet to drive the car.

The two R-Ones will run in Le Mans aero configuration at Spa by way of preparation for Le Mans.

The cars will return to ORECA's base adjacent to Paul Ricard after Spa and are scheduled to undertake a three-day test at the circuit in mid-May ahead of the Le Mans Test Day on June 1.